Multi-Speed Planetary Drive For A Supercharger
A multi-speed drive for a supercharger includes a planetary gear mechanism with a sun gear mechanism, a plurality of planet gears mounted on a planet carrier, and a ring gear, all mounted for rotation on a stationary shaft. A rotary-mechanical drive input is received by either the ring gear or the planetary drive, and a rotary-mechanical drive output is provided by the planetary drive when the ring gear receives the input, or by the ring gear when the planetary drive receives the input. A one-way roller clutch is disposed coaxially with the planetary gear mechanism, between the sun gear mechanism and the stationary shaft. A hydraulically-actuated, clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages the sun gear and the ring gear to change the gear ratio of the drive.
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The field of the invention is a drive with a variable transmission for controlling the speed of a supercharger of an internal combustion engine. More particularly, the field relates to driving a supercharger at multiple speeds using a planetary gear assembly.
BACKGROUND OF THE INVENTIONAn internal combustion engine requires different amounts of intake air under different operating conditions. For example, in order to increase engine speed, the air handling system may be required to increase (boost) the pressure (or density) of intake air so as to provide more oxygen to burn more fuel, thereby increasing the power delivered by the engine. To pressurize intake air on demand, the air handling system may include a supercharger, which is an air compressor driven by a mechanical coupling to an engine crankshaft. However, if a supercharger is designed for operation at low engine speeds, the supercharged intake air pressure at high speeds may be higher than necessary for optimal operation. Similarly, if the supercharger is designed for operation at high engine speeds, the supercharged intake air pressure will be insufficient to generate sufficient torques at low speeds. Therefore, there is need for a drive device that allows the supercharger to operate efficiently at both high and low engine speed conditions.
In modern vehicles such as trucks and automobiles, engine compartment space for auxiliary devices such as superchargers may be very limited. The room available for a supercharger drive may be further limited due to a need to locate the supercharger in close proximity to a crankshaft for coupling. So it is desirable that a multi-speed drive for a supercharger be as compact as possible while providing functionality which enables multi-speed supercharger operation. This is achieved in the supercharger drive embodiments described below by using a planetary gear-set and a multidisc clutch mechanism mounted for rotation on a stationary shaft.
SUMMARY OF THE INVENTIONOne aspect of the invention relates to a multi-speed drive for a supercharger having a planetary gear mechanism with a sun gear assembly, a plurality of planet gears mounted on a planet carrier, and a ring gear, all mounted for rotation on a stationary shaft. A rotary-mechanical drive input is received by either the ring gear or the planet carrier, and a rotary-mechanical drive output is provided by the planet carrier when the ring gear receives the input, or by the ring gear when the planet carrier receives the input. A one-way roller clutch is disposed coaxially with the planetary gear mechanism, between the sun gear assembly and the stationary shaft. A hydraulically-actuated, multiplate clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages the sun gear and the ring gear to change the gear ratio of the drive.
An aspect of the invention involves a multi-speed drive for a supercharger in which a planetary gear mechanism mounted for rotation on a stationary shaft receives a rotary-mechanical input via a ring gear and provides a rotary-mechanical output by way of a planet carrier. A hydraulically-actuated, multiplate clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages a sun gear and the ring gear. The multiplate clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together. A one-way roller clutch disposed coaxially with the planetary gear mechanism is operable to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
In some instances of the invention a drive input from the engine is received by the ring gear, and the drive output for the supercharger is taken from the planet carrier. In a low speed drive mode, the multiplate clutch assembly unlocks the sun gear assembly from the ring gear while the one-way clutch prevents the sun gear assembly from rotating, causing the ring gear to rotate the planet carrier at a first speed. In a high speed drive mode, the multiplate clutch assembly locks the sun gear assembly to the ring gear, causing all three planetary gear elements to rotate at a second speed which is higher than the first speed.
Another aspect of the invention involves a multi-speed drive for a supercharger in which a planetary gear mechanism mounted for rotation on a stationary shaft receives a rotary-mechanical input via a planet carrier and provides a rotary-mechanical output by way of a ring gear. A hydraulically-actuated, multiplate clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages a sun gear and the ring gear. The multiplate clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together. A one-way roller clutch disposed coaxially with the planetary gear mechanism is operable to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
In some other instances of the invention a drive input from the engine is received by the planet carrier and the drive output for the supercharger is taken from the ring gear. In a high speed drive mode, the multiplate clutch assembly unlocks the sun gear assembly from the ring gear while the one-way clutch prevents the sun gear assembly from rotating, causing the planet carrier to rotate the ring gear at a first speed. In a low speed drive mode, the multiplate clutch assembly locks the sun gear assembly to the ring gear, causing all three planetary gear elements to rotate at a second speed which is lower than the first speed.
Generally, a multi-speed supercharger drive according to this specification is embodied in an internal combustion vehicle engine including an air handling system equipped with a supercharger powered by rotary mechanical motion coupled from a crankshaft. In this regard, see the example illustrated in
Referring to
Certain embodiments of the invention will be described now with reference to the
Thus assembled the supercharger drive 60 of
Selection of the supercharger drive mode of operation is enabled by a clutch assembly that engages the sun gear assembly 83 and the ring gear 107. Preferably, the clutch assembly is a hydraulically-actuated, multiplate clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft. In this regard, with reference to
Presume that a rotary mechanical input from the crankshaft is applied to the input pulley, causing the pulley 79, the clutch housing 75, and the ring gear 107 to rotate in response to crankshaft rotation. Rotation of the ring gear 107 causes rotation of the planet gears 130, and thereby the planet carrier 118, in the same direction as the ring gear 107. Rotation of the planet carrier 118 is output to the supercharger via the output pulley 137.
With the hydraulically-actuated, multiplate clutch assembly illustrated in
The second mode of the supercharger drive operation is indicated by the presence of fluid pressure in the space between the piston support disc 150 and the piston disc 152. This will cause the piston disc 152 to exert a mechanical pressure against the clutch plates 150. With pressure exerted by the piston disc 152, the first and second clutch plates 156 and 157 are brought into close frictional contact; that is to say, the clutch is closed. With frictional contact between the clutch plates 150, the sun gear assembly 83 is locked to the ring gear 107 and rotates in the same direction, and at the same speed, as the ring gear 107. This locks the planet carrier 118 between the sun gear assembly 83 and the ring gear 107 in a direct drive configuration in a direct drive configuration in which all three elements of the planetary gear assembly rotate together at the same speed. Thus, the speed of the output pulley 137 and the speed of the supercharger driven thereby are increased relative to the output speed of the drive in the first mode of operation.
Second EmbodimentThus assembled the supercharger drive 160 of
Selection of the supercharger drive mode of operation is enabled by a clutch assembly that engages the sun gear assembly 183 and the ring gear 207. Preferably, the clutch assembly is a hydraulically-actuated, multiplate clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft. In this regard, with reference to
Presume that a rotary mechanical input from the engine is applied to the input pulley, causing the pulley 279 and the planet carrier 218 to rotate in response to crankshaft rotation. Rotation of the planet carrier 218 causes rotation of the planet gears 230 thereby rotating the ring gear 207 in the same direction as the planetary carrier 218. Rotation of the ring gear 207 is output to the supercharger via the clutch housing 175 and the output pulley 178.
With the hydraulically-actuated, multiplate clutch assembly illustrated in
The second mode of the supercharger drive operation is indicated by the presence of fluid pressure in the space between the piston support disc 250 and the piston disc 252. This will cause the piston disc 252 to exert a mechanical pressure against the clutch plates 255. With pressure exerted by the piston disc 252, the first and second clutch plates 256 and 257 are brought into close frictional contact; that is to say, the clutch is closed. With frictional contact between the clutch plates 255, the sun gear assembly 183 is locked to the ring gear 207 and rotates in the same direction, and at the same speed, as the ring gear 207. This locks the planet carrier 218 between the sun gear assembly 183 and the ring gear 207 in a direct drive configuration in which all three elements of the planetary gear assembly rotate at the same speed. Thus, the speed of the output pulley and the speed of the supercharger driven thereby are decreased relative to the output speed of the drive in the first mode of operation.
The foregoing description details certain embodiments of the invention. However, no matter how detailed the foregoing appears in text, the invention can be practiced in many additional ways. Furthermore, use of particular terminology when describing certain features or aspects of the invention is not meant to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated. The scope of the invention described hereinabove is therefore to be determined solely by the language of the following claims.
Claims
1. A multi-speed drive for a supercharger, comprising:
- a stationary shaft:
- a planetary gear mechanism with a sun gear mechanism, a plurality of planet gears mounted on a planet carrier, and a ring gear, all mounted for rotation on the stationary shaft;
- a rotary-mechanical drive input being received by either the ring gear or the planet carrier, and a rotary-mechanical drive output being provided by the planet carrier when the ring gear receives the input, or by the ring gear when the planet carrier receives the input;
- a one-way roller clutch disposed coaxially with the planetary gear mechanism, between the sun gear mechanism and the stationary shaft; and,
- a hydraulically-actuated, clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft, and operably engaging the sun gear and the ring gear to change a gear ratio of the multi-speed drive.
2. The multi-speed drive of claim 1, in which:
- the planetary gear mechanism receives the rotary-mechanical input via the ring gear and provides the rotary-mechanical output by way of a planet carrier;
- the clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together;
- the one-way roller clutch is disposed to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
3. The multi-speed drive of claim 2, wherein, in the first state, when the sun gear assembly is unlocked from the ring gear while the sun gear assembly is prevented from rotating, the ring gear is operable to rotate the planet carrier at a first speed, and, in the second state, when the sun gear assembly is locked to the ring gear, the ring gear, the sun gear assembly, and the planet carrier are operable to rotate together at a second speed that is higher than the first speed.
4. The multi-speed drive of claim 2 or claim 3, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
5. The multi-speed drive of claim 1, in which:
- the planetary gear mechanism receives the rotary-mechanical input via the planet carrier and provides the rotary-mechanical output by way of the ring gear;
- the clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together; and,
- the one-way roller clutch is disposed to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
6. The multi-speed drive of claim 5, wherein, in the first state, when the sun gear assembly is unlocked from the ring gear while the sun gear assembly is prevented from rotating, the planet carrier is operable to rotate the ring gear at a first speed, and, in the second state, when the sun gear assembly is locked to the ring gear, the ring gear, the sun gear assembly, and the planet carrier are operable to rotate together at a second speed that is lower than the first speed.
7. The multi-speed drive of claim 5 or claim 6, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
8. A multi-speed drive for a supercharger, in which:
- a planetary gear mechanism mounted for rotation on a stationary shaft receives a rotary-mechanical input via a ring gear and provides a rotary-mechanical output by way of a planet carrier;
- a hydraulically-actuated, clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages a sun gear and the ring gear;
- the clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together;
- a one-way roller clutch is disposed coaxially with the planetary gear mechanism to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
9. The multi-speed drive of claim 8, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
10. The multi-speed drive of claim 8, wherein, in the first state, when the sun gear assembly is unlocked from the ring gear while the sun gear assembly is prevented from rotating, the ring gear is operable to rotate the planet carrier at a first speed, and, in the second state, when the sun gear assembly is locked to the ring gear, the ring gear, the sun gear assembly, and the planet carrier are operable to rotate together at a second speed that is higher than the first speed.
11. The multi-speed drive of claim 10, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
12. A multi-speed drive for a supercharger, in which:
- a planetary gear mechanism mounted for rotation on a stationary shaft receives a rotary-mechanical input via a planet carrier and provides a rotary-mechanical output by way of a ring gear;
- a hydraulically-actuated, clutch assembly mounted coaxially with the planetary gear mechanism on the stationary shaft engages a sun gear and the ring gear;
- the clutch assembly is operable in a first state to unlock the sun gear assembly from the ring gear, and is operable in a second state to lock the sun gear assembly and the ring gear together; and,
- a one-way roller clutch is disposed coaxially with the planetary gear mechanism to prevent rotation of the sun gear assembly when the sun gear assembly is unlocked from the ring gear.
13. The multi-speed drive of claim 12, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
14. The multi-speed drive of claim 12, wherein, in the first state, when the sun gear assembly is unlocked from the ring gear while the sun gear assembly is prevented from rotating, the planet carrier is operable to rotate the ring gear at a first speed, and, in the second state, when the sun gear assembly is locked to the ring gear, the ring gear, the sun gear assembly, and the planet carrier are operable to rotate together at a second speed that is lower than the first speed.
15. The multi-speed drive of claim 14, in which the hydraulically-actuated clutch assembly is a multiplate clutch assembly.
Type: Application
Filed: Sep 1, 2015
Publication Date: Mar 2, 2017
Patent Grant number: 9927006
Applicant: Achates Power, Inc. (San Diego, CA)
Inventors: Sumanth Kashyap (San Diego, CA), Balazs V. Palfai (Foster City, CA)
Application Number: 14/841,969